Rehospitalization is common following an operation with 16% of Medicare beneficiaries readmitted at 30 days and nearly 50% at one year.[1] Some of the highest rates of readmission occur in patients undergoing complex cancer resections.[3-7] To date, research into the etiology, mechanisms, and impact of readmissions has focused almost exclusively on the providers, institutions, and payors, likely due to the high cost and burden on the healthcare system that these readmissions pose. Little is known about the impact of readmission on individual patients, including on patient-centered outcomes. Incorporating the patient's perspective into studies of readmission is critical to ensuring that interventions designed to reduce readmissions also improve the patient's experience. The finding that nearly 50% of readmissions are potentially preventable [2] suggests an opportunity for improvement. Prior studies evaluating risk factors for readmission have utilized administrative data to evaluate the etiology of readmission, but lack the granularity necessary to completely understand this problem, including the perspective of and impact on individual patients.[4-7] This proposal seeks to evaluate the etiology of readmission following complex cancer surgery from the patient's perspective, utilizing a systems engineering approach, in particular, the Systems Engineering Initiative for Patient Safety (SEIPS) model.[9] The aims of this K18 Career Enhancement Award application are to: 1) Utilize a systems engineering approach to examine the etiology of readmission from the patient's perspective following complex cancer surgery. Using the SEIPS model, assessment of the work system will be performed, including assessment of contributing and mitigating factors at the level of the care team, patient, organization, technology/tools, tasks, and work environment. 2) Develop a comprehensive model of factors that contribute to readmission after complex cancer surgery that includes the patient's and provider's perspective. Data synthesis using a mixed methods approach will assess common themes. Dr. Sharon Weber is a tenured Professor of Surgery who is nationally recognized for her accomplishments in clinical care, research and leadership, but could benefit significantly from formal training and mentoring in health systems research with an emphasis on patient-centered outcomes research. The primary mentor, Dr. Pascale Carayon, Director of the Center for Quality and Productivity Improvement, developed the SEIPS model and her expertise will be invaluable. In addition, co-mentor Caprice Greenberg, MD, MPH, is Director of Wisconsin Surgical Outcomes Research (WiSOR) program, affiliate faculty in systems engineering, and will form an essential part of the mentoring team due to her extensive experience in PCOR and stakeholder engagement. The career development plan includes didactics, research, and individualized mentoring. The environment is ideal with a solid infrastructure for support of health services research and history of collaboration between the Department of Surgery and the College of Engineering.